Merge "Trivial: Remove unuseful doc of "network list" command."

Author: Jenkins

doc/source/command-objects/network.rst

@@ -74,17 +74,12 @@ List networks
 
     os network list
         [--external]
-        [--dhcp <dhcp-id>]
         [--long]
 
 .. option:: --external
 
     List external networks
 
-.. option:: --dhcp <dhcp-id>
-
-    DHCP agent ID
-
 .. option:: --long
 
     List additional fields in output